Cardiovascular test station pressurometer interface system

ABSTRACT

A pressurometer interface circuit operative to provide serial, binary data representative of patient pulse rate and patient systolic and diastolic blood pressures. In response to automatic inflation and deflation of a cuff the interface circuit receives in parallel a plurality of bilevel signals, each associated with a given cuff pressure and indicating whether a Korotkoff sound response is detected at the cuff pressure. The bilevel signals are converted, for efficient data communication, to serial binary coded data representative of the boundaries of the range of pressures during which Korotkoff sounds are exhibited. Further binary data is generated indicating patient pulse rate as interpreted from the Korotkoff sounds during deflation.

United States Patent [191 Murphy, Jr. eta].

[ Dec. 18, 1973 [54] CARDIOVASCULAR TEST STATION 3,654,915 4/1972Sanctuary 128/205 M PRESSUROMETER INTERFACE SYSTEM [75] Inventors:William Murphy Jr Primary liraminer-William E. Kamm Framingham; JosephB. Ferguson, Att0rneyWemgarten et al. Harvard; Edward B. Rawson,Lincoln, all of Mass. [57] ABSTRACT Assigneei Searle Medidata w walthamA pressurometer interface circuit operative to provide Massserial,binary data representative of patient pulse rate 22 Filed; June 18, 197and patient systolic and diastolic blood pressures. In response toautomatic inflation and deflation of a cuff [2]] Appl' 154,561 theinterface circuit receives in parallel a plurality of bilevel signals,each associated with a given cuff pres- 52 mg 2 /2 05 My 128/206 R128/21 A sure and indicating whether a Korotkoff sound re- [51 int. ClA6lb 5/02 Sponse is detected at the Cuff Pressure The bilevel [58] Fieldof Search 128/205 A, 2.05 D, nals are converted, for efficient dataCommunication 12 2 5 G 5 M, 205 N, 205 p 205 Q to serial binary codeddata representative of the 2 5 R, 2 5 T, 2 A 2.06 G 206 R boundaries ofthe range of pressures during which Korotkoff sounds are exhibited.Further binary data is 5 References Cited generated indicating patientpulse rate as interpreted UNITED STATES PATENTS from the Korotkoffsounds during deflation.

3,202,148 8/1965 London 7. 128/205 D 15 Claims, 3 Drawing Figures ENDTEST MULTIPLEXER MULTIPLEXERS 46 SAMPLE 0 (58 8 F HOLD 36 |8 48 L 34 g4O 5O 62 ECL. CONSOLE ATTENUATE 52 Q E 28 a 54 Q g INVERT] ADDRESS 38100 9e g j l MULTIPLEXER C NT R REPEAT a 56 l LU l g L /68 32 2 44 TCOUNTER COUNTER 7O TONOMETER EXHAUSTION SIGNAL I v r l L 90 K- SOUND OGATE PULSE SHAPER 86 ELECTROCARDIOGRAPH DEFLATION SIGNAL DETECT j 82 92CARDIOVASCULAR TEST STATION PRESSUROMETER INTERFACE SYSTEM FIELD OF THEINVENTION This invention relates to electronically automated medicalexamination of patients and in particular to data interfacing forpressurometer testing.

BACKGROUND OF THE INVENTION Modern medical examination procedures areplacing increasing reliance upon electronics for gathering the responseof patients to a variety of new and traditional patient tests. One ofthe traditional tests being performed electronically today is thereading of patient pulse rate and blood pressure. Several units arecommercially available, such as the Avionics Research Products,Pressurometer Model 1900, which provide a visual display of thecorrelation between patient blood pressure and the existence of patientKorotkoff sounds. Korotkoff sounds are noise generated by blood flowingthrough vessels which are partially constricted in response to thedegree of inflation of an inflatable cuff wrapped around a patientsextremity. Patient systolic and diastolic pressure levels, the medicallysignificant parameters of a patients blood pressure, are indicated bythe largest and smallest pressures for which Korotkoff sounds aredetected by the pressurometer.

While such a pressurometer greatly simplifies the task of obtainingpatient blood pressure data, manual reading of the pressurometer scalesand manual recording of pressure data is still required. This additional.work reduces the efficiency of blood pressure testing and increases itscost as well as the chance of error. A need clearly exists for anelectronic system capable of directly converting pressurometer outputformat into machine readable binary signals representative of patientdiastolic and systolic pressure. At the same time, significantefficiency in medical data taking can be gained if patient pulse ratecan be determined during the blood pressure test to avoid the necessityof connecting additional apparatus to the patient to sample this pulserate. Finally, since pressurometer data may have to be transmitted overa distance through a data link, data should be presented to the datalink in a form allowing for efficient communication.

SUMMARY OF THE INVENTION An interface circuit is provided operative withavailable pressurometer units of the type which correlate patient bloodpressure with the presence of Korotkoff sounds, the interface circuitproviding, in serial bit form, binary coded signals representing patientdiastolic and systolic blood pressures and patient pulse rate forsubsequent machine data processing.

In pressurometers of the type indicated, a plurality of selectivelyilluminated lamps are provided with each lamp corresponding to aparticular patient blood pressure level. The pressurometer is operativeto cycle an inflatable cuff through an inflation and deflation sequenceand during deflation the selectively illuminated lamps are lighted inresponse to detection of Korotkoff sounds at the patient pressure levelcorresponding to each lamp.

Also during cuff deflation detected Korotkoff sounds are pulse shapedand encoded into a uniquely recognizable serial, binary sequence andconveyed to a station console and associated central processor in realtime sequence to indicate patient pulse rate.

After complete deflation and evacuation of the cuff, the interfacecircuit switches to a blood pressure mode in which the status of thepressurometer lamps are sequentially sampled to enable the generation ofbinary coded signals representing diastolic and systolic pressurelevels. The interface circuit performs this function by sequentiallysampling the status of each lamp and detecting the existence of adifferent lamp status between adjacent pressure levels, indicative of atransition between Korotkoff sounds and no Korotkoff sounds at thecorresponding pressure level. Upon the detection of a lamp statustransition, the identity of a lamp adjacent the transition isautomatically read out in serial binary form and conveyed to the centralprocessing unit via the test station console.

DESCRIPTION OF THE DRAWINGS These and other features of the inventionwill be more fully understood by reference to the following detaileddescription of a preferred embodiment, presented for purposes ofillustration and not by way of limitation and to the accompanyingdrawings of which:

FIG. 1 is a pictorial view of a pressurometer interface circuit in acardiovascular test station; and

FIG. 2 is a partial schematic and partial block diagram of an interfacecircuit according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In the realm of medicalscience the taking of patient blood pressure information is achieved bystrapping an inflatable cuff around a patients arm, or other extremity,and inflating the cuff to the point where the circulation. of arterialblood flow in vessels is inhibited. Cuff pressure is then reduced at aslow, controlled rate until the attending physician detects, through theuse of a stethoscope, the presence of Korotkoff sounds indicating thebeginning of blood flow through the constricted blood vessels. Thepressure at which Korotkoff sounds are first noticed is known as thesystolic blood pressure level. With further cuff deflation, a pressureis reached where Korotkoff sounds are last noticed, and this pressure istermed the diastolic pressure level.

Referring now to FIG. 1, there is shown a cardiovascular test stationset up for measuring patient blood pressure and pulse rate and utilizinga pressurometer interface circuit 12 according to the invention. In theexample of FIG. 1, a patient 14 has an inflatable cuff l6 wrapped aroundhis arm and connected to a pressurometer 18 of the type exemplified byAvionics Research Products, Pressurometer Model 1900. A pressure pumpand a release valve, not shown, within the pressurometer 18, areconnected through pneumatic tubing 20 to the cuff 16. Within the cuff 16a detector 22 senses blood vessel Korotkoff sounds and conductselectrical representations thereof over a line 24 to the pressurometer18.

In operation, the pressurometer 18 is automatically, or manually, cycledto provide inflation pressure to the cuff l6, pressurizing it to a pointwhere all blood flow through the vessels of the arm is eliminated. Thepressurometer 18 then deflates the cuff 16 at a predetermined rate untilthe cuff is exhausted.

During deflation of the cuff l6, detection circuitry within thepressurometer 18 samples the signal on line By appropriate connectionwithin the pressurometer 18, a plurality of electrical lines 28 areprovided from the pressurometer 18 to the interface circuit 12, witheach line carrying a signal representative of the status of acorresponding lamp in the set 26. Additionally, a signal representativeof the detected Korotkoff sounds is conducted from the pressurometer 18over a line 30 to the interface circuit 12, a signal indicating that thecuff is deflating is fed to the interface over line 31, and a signalindicating cuff exhaustion is provided from the pressurometer 18 over aline 32 to the interface circuit The pressurometer interface circuit 12converts the plurality of inputs containing pulse rate and pressureinformation into serial data and conveys it, via a single line 34,through a data link 35, to a cardiovascular station console 36. The datalink 35 may include substantial distance and it is, therefore, aneconomic benefit that data is in serial bit form and-only necessitates asingle. data line 34. Supervisory and clock signals are provided bypreferably a single line 38 from the console 36 to the interface circuit12.

Referring to FIG. 2, and the more detailed description of the interfacecircuit 21, the plurality of lamp condition lines 28 are conducted to anattenuator and inverter circuit 40 which provides signal levelnormalization of the lamp status signals through a plurality ofcorresponding voltage dividers 42 and transistor driving circuits 44 inorder to match level requirements for the interface circuit 12. Theplurality of normalized lamp condition signals are bunched in groups of,for example, six signals, each group leading into one of a plurality ofprimary multiplexer circuits 46 through 56. An output from each primarymultiplexer 46-56 is conducted to a secondary multiplexer circuit 58along with an end of test signal. The output of the secondarymultiplexer 58 is conducted to a sample and temporary hold circuit 60and to one input of an exclusive OR gate 62. The output of the sampleand hold circuit 60 is conducted to a second input of the exclusive ORgate 62. The output of the exclusive OR gate 62 is conducted to ajunction circuit 64 which in turn passes the signal of gate 62 to a gate66 that feeds the data line 34 to the test station console 36 via datalink 35.

The supervisory signal on line 38 from the console 36 comprises a clocksignal conducted, through an amplifier 67, to a binary counter 68 thatcounts through a plurality of steps in a predetermined count includingone step for each of the lamps in the pressurometer l8 and at least oneadditional step for control purposes. A further counter 70 receives theclock signal on line 38 and provides a binary count through apredetermined number of steps for each step of the counter 68. Thebinary states of the counter 70 are fed in parallel to an addressmultiplexer 72 along with the binary states, in parallel, from thecounter 68. The binary states of the counter 68 are also applied to theprimary multiplexers 46 through 56 and to the secondary multiplexer 58.

The counter 68 has a reset and enable signal provided to it over line32.

When appropriately reset and enabled, the counter 68 operates to countthrough the steps of its predetermined count in response to the clocksignal on line 38. Each of the primary multiplexers 46 through 56 isadapted to recognize a predetermined binary state in the count ofcounter 68 in an exclusive range for each primary multiplexer and toprovide an output signal representative of the one of its inputs whichcorresponds to the particular binary state of the counter 68. Thesecondary multiplexer 58 is adapted to recognize the exclusive ranges ofbinary states from the counter 68 and provide at its output a signalrepresentative of the signal input thereto from the particular one ofthe primary multiplexers in the corresponding exclusive range of binarystates recognized. In this fashion the primary multiplexers 46 through56 and the secondary multiplexers 58 operate as a single pole multiplethrow switch cycling in correspondence with the states of the counter 68to sample each of the plurality of inputs to the primary multiplexersand to provide at an output of the secondary multiplexer a signalrepresenting the status of the input sampled.

The output of the multiplexer 58 is sampled by the sample and holdcircuit 60 and held for the duration of one step in the counter 68 suchthat its output is representative of the condition of the lamppreviously sampled. The exclusive OR gate 62 receives as inputs thecurrent and previously sampled lamp conditions and provides an outputindicating when its two inputs differ. The two inputs differ in responseto a transition between lighted andunlighted lamps and correspondingly atransition between the existence of Korotkotf sounds and non-existenceof Korotkoff sounds.

The output of the exclusive OR gate 62, indicating this transition, isconducted through the junction circuit 64 to the gate 66 where it causesthe gate 66 to respond to and pass the signal from the addressmultiplexer 72. The address multiplexer 72 operates to provide, as itsoutput to the gate 66, a sequence of binary signals representative ofthe state of the counter 68 at the time of detected transition. Thecounter 70 effects the sampling of the state of the counter 68 bycausing the multiplexer 72 to sample each of the binary states ofcounter 68 in correspondence with the count of the counter 70. Theoutput of the multiplexer 72, in response to a transition, comprises aninitial bit of predetermined information followed by binary signalsindicating the state of binary counter 68. The output of the sample andhold circuit 60 is also applied to the multiplexer 72 which encodes thatsignal in the last bit of data provided from the multiplexer.

The end of test signal applied to secondary multiplexer 58 causesdetection of an artificial transition beyond the pressure range of thepressurometer and thus produces a signal which is communicated to theconsole 36 to indicate the completion of a test. The console 36operating with a central processing unit or computer 74 recognizes theend of test address and operates to preclude further testing for thatpatient unless an override is activated. The interface can be signaledto stop testing, by, for example, removing the clock signal.

The Korotkoff sounds and the cuff deflation and exhaustion statussignals from the pressurometer 18 are applied respectively over lines30, 31 and 32 to the circuits of FIG. 2. The Korotkoff sounds on line 31are applied to a gate 82. The cuff deflation signal on line 31 isapplied to a detector 84 which provides an enable signal to gate 82 whenthe cuff is in the deflation portion of an inflation-deflation cycle.The Korotkoff sounds are conducted from gate 82 during deflation only,to eliminate noise interference from rapid inflation, and applied to apulse shaper circuit 86 which also receives the clock signal andproduces an output pulse of appropriate shape to reflect patient pulsewhich it represents synchronized with the clock signal on line 38. Thissignal is conducted to junction circuit 64 and thence to gate 66. Thesignal from multiplexer 72 to gate 66 is normally at an enable level andthus permits passage of the clocked pulse signals through gate 66 toconsole 36 to indicate patient pulse.

The cuff exhaustion signal on line 32 is fed to counters 68 and 70 andresets the counters 68 and 70. Prior to exhaustion, this signal byapplication to counters 68 and 70 prevents counter operation and thusinhibits system operation but after cuff exhaustion by resettingcounters 68 and 70 enables the system operation described above andthereby causes the lamps of the pressurometer 18 to be sampled and readout through gate 66.

As shown in FIG. 1 and FIG. 2 the console 36 is a central control systemfor a cardiovascular station which includes a manual or automatictonometer 90 and a manual or automatic electrocardiograph 92 communicating with the console 36 to provide patient data in response tocontrol signals. All tests are conveniently performed with the patientin a horizontal position. As shown in FIG. 2 the central processing unit74 is operative in conjunction with the console 36 to receive patientdata and perform appropriate calculations thereon to provide indicia ofpatient cardiovascular condition. In response to data on patient bloodpressure and pulse rate, the console 36 communicates this data to thecentral processing unit 74 which, after calculation of blood systolicand diastolic pressures and pulse rate, returns this information to theconsole for presentation on a display 96. An enter button 98 is providedon the console 36 to cause the central processing unit 74 to record thedisplayed data as part of the patients medical information in responseto activation of the entry button 98 when the test operator is satisfiedwith the appearance of the data. A repeat button 100 is provided toenable recycling of the test if the data is unsatisfactory. When thebutton 100 is depressed, the clock signal is reapplied and the test isrecycled in response to activation of a cycle button on thepressurometer.

Having described a preferred embodiment of the present invention, itwill occur to those skilled in the art that modifications andalterations can be made to the specific disclosure while accomplishingthe spirit of the invention. It is accordingly intended to limit thescope of the invention only as indicated in the following claims.

What is claimed is:

l. A pressurometer interface circuit operative to provide patientdiastolic and systolic pressure data from a pressurometer of the typehaving a cyclically inflatable cuff and a plurality of bilevel signals,each associated with a particular cuff pressure, and being in one of thetwo levels in response to the presence of Korotkoff sounds at thecorresponding cuff pressure and in the second of the two levels inresponse to the absence of Korotkoff sounds at the correspondingpressure, said interface circuit comprising:

means for receiving said plurality of bilevel signals;

means for sequentially sampling the level of each of said receivedbilevel signals to provide a sequence of sampled signals eachrepresenting a corresponding bilevel signal;

said sampling means including means for providing an indication of whichof said bilevel signals is sampled;

means for detecting a difference in signal level of ad jacent signals insaid sequence of sampled signals; and

means responsive to detection of a difference in sig nal level forgenerating an address signal in serial bit form to represent thesampled, adjacent bilevel signals detected as different, thereby toprovide output indicia of said patient diastolic and systolic pressuredata.

2. The pressurometer interface circuit of claim 1 further comprising:

means for adjusting the signal level of said received plurality ofbilevel signals to a predetermined range of levels compatible with saidinterface circuit. 3. The pressurometer interface circuit of claim 1further including:

means responsive to deflation of the pressurometer cuff for generatingpulses coincident with patient Korotkoff sounds; and

means responsive to cuff exhaustion for inhibiting the generation ofsaid pulses and for enabling sampling by said sampling means of saidplurality of bilevel signals.

4. In combination with a pressurometer interface circuit of the typeclaimed in claim 1 further apparatus including:

means for transmitting said generated serial bit form address signal;

a test station console for receiving said address signal; and

a central computation facility in communication with said console fordata processing of said address signal as received by said console toprovide diastolic and systolic pressure data;

said console, in association with said central computation facility,having means responsive to said dia stolic and systolic pressure datafrom said central computation facility for displaying said data at saidconsole;

said console further having means for causing said central computationfacility to record said diastolic and said systolic pressure data inresponse to activation thereof.

5. The apparatus and pressurometer interface circuit of claim 4 furtherincluding means for causing recycling of said interface andpressurometer for additional testing in response to activation thereof.

6. The pressurometer interface circuit of claim 1 wherein said samplingmeans further includes:

a multiplexer system receiving said plurality of adjusted, bilevelsignals at parallel inputs thereof; and

a counter operating at a predetermined frequency to count through apredetermined number of steps; said multiplexer system operating inresponse to the counting of said counter to provide at an output of saidmultiplexer system said sequence of sampled signals;

each step in the count of said counter causing said multiplexer toprovide at the output thereof one signal of said sequence of-sampledsignals in correspondence with that step in the count.

7. The pressurometer interface circuit of claim 1 wherein said addresssignal generating means includes means for providing an indication insaid address signal of the level of one said adjacent, different bilevelsignals.

8. The pressurometer interface circuit of claim 1 wherein said samplingmeans includes means for providing a signal of a predetermined level insaid sequence to indicate the end of said sequence.

9. An interface circuit operative in association with a bloodpressurometer of the type having a blood flow restricting inflatablecuff cyclable through an inflate and deflate sequence andadapted tosense the Korotkoff sounds during at least a portion of the sequence,said pressurometer further including a plurality of two display stateelements each associated with a particular pressure in a range ofpressures for said cuff, said pressurometer adapted to cause each ofsaid two state elements to change from a first display state to a seconddisplay state in response to the existence of said Korotkoff sounds atthe corresponding pressure level of each said element during deflationof said cuff, said interface circuit comprising:

means for sensing the state of each of said plurality of two stateelements;

means for developing a plurality of bilevel signals,

each representative of the sensed state of a corresponding two stateelement;

means for adjusting each said bilevel signal in signal level to apredetermined data logic scheme;

multiplexer means for receiving each of said plurality of bilevelsignals on one of a plurality of parallel inputs;

a binary counter operative to count at a predetermined rate through apredetermined number of binary steps;

said multiplexer means being operative in response to the count of saidcounter to provide as an output signal, a signal representative of thelevel of an input to said receiving means corresponding to the count ofsaid counter in order to provide at the output of said multiplexer meansa sequence of signals representative of the signal level at each of saidplurality of parallel inputs to said multiplexer means;

means for sampling and retaining for approximately one step of saidcounter each signal in said sequence of signals at the output of saidmultiplexer means;

means for comparing each signal in the sequence of signals from saidmultiplexer means with the signal retained by said sampling andretaining means;

said comparing means providing an indication of a difference betweenadjacent signals at the output of said multiplexer means; and

means for generating a signal representative of the count of said binarycounter coincidental with the indication by said comparing means ofdifferent adjacent signals in said sequence.

10. The interface circuit of claim 9 further including:

means for sensing Korotkoff sound signals from said pressurometer;

means for producing a signal representative of said sensed Korotkoffsound signals;

means for sensing the state of inflation of said cuff by saidpressurometer;

means for enabling the production of said signals representative ofKorotkoff sound signals only during relatively noise free portions of aninflate-deflate cycle; and

means for inhibiting said counter whenever said sensed cuff statusindicates partial or complete cuff inflation;

said counter being operative in response to said sensed cuff status tocommence counting at a predetermined count whenever said cuff statussignal indicates cuff exhaustion after an inflate-deflate cycle.

11. The interface circuit of claim 10 further includ ing:

means for indicating the inflation status of said cuff;

means responsive to the indicated deflation of said cuff and the sensedKorotkoff sounds for producing patient pulse signals in serial bit form;and

means for alternatively transmitting said generated and said producedsignals.

12. The interface circuit of claim 9 wherein saidgen erating meansfurther includes:

second multiplexer means for receiving the binary states of saidcounter;

a second counter counting at a predetermined higher rate than the firstmentioned counter;

said second multiplexer means including means responsive to the countsequence of said second counter for providing as an output a sequence ofsignals representative of the binary states of said first counter asapplied to said second multiplexer means.

13. The interface circuit of claim 9 further including means for causingsaid generating means to generate an end of sequence signal when saidbinary counter has counted through said predetermined number of binarysteps.

14. The interface circuit of claim 9 having apparatus associatedtherewith including:'

a serial bit data link means for applying said generated signal to saiddata link;

control means for recovering said generated signal from said data linkand for applying a supervisory signal-to said data link;

said interface circuit including means for recovering said supervisorysignal from said data link and for applying said recovered supervisorysignal to control said binary counter;

said control means having means for determining and displaying patientcardiovascular data in response to said recovered generated signal andfurther including means having first and second states to record saiddata in said first state and to enable, with said supervisory signal,said interface circuit to generate further signals in said second state.

15. The interface circuit and apparatus of claim 14 further including:

a tonometer test unit; and

an electrocardiograph test unit;

means for interconnecting said units with said control means forprocessing received test information.

* t I 8 i UNITED STATES PATENT OFFICE CERTIFICATE CORRECTION Patent e;779,235 Dated December 18, 1973 Inventor()William J. Murphy, Jr Josph B.Ferguson and v Edward B. Rawson v lt li oertified that error appears inthe above-identified patent andfthat said Letters Patent. are herebycorrected as shown below:

" lin elss, "circuit 21" shoud read circ uit 12- "'line' 31" shouldfeadljfne 30".

I this 19th dy of Nmfember' I ("SE LI Me's-0y ILKfGIBSQIi: 'JIRQ I Y ,c.MARSHALL. DANN Atte'stiggigpffiicer" j Commissioner of Patents FORMPC4050 U0-69)

1. A pressurometer interface circuit operative to provide patientdiastolic and systolic pressure data from a pressurometer of the typehaving a cyclically inflatable cuff and a plurality of bilevel signals,each associated with a particular cuff pressure, and being in one of thetwo levels in response to the presence of Korotkoff sounds at thecorresponding cuff pressure and in the second of the two levels inresponse to the absence of Korotkoff sounds at the correspondingpressure, said interface circuit comprising: means for receiving saidplurality of bilevel signals; means for sequentially sampling the levelof each of said received bilevel signals to provide a sequence ofsampled signals each representing a corresponding bilevel signal; saidsampling means including means for providing an indication of which ofsaid bilevel signals is sampled; means for detecting a difference insignal level of adjacent signals in said sequence of sampled signals;and means responsive to detection of a difference in signal level forgenerating an address signal in serial bit form to represent thesampled, adjacent bilevel signals detected as different, thereby toprovide output indicia of said patient diastolic and systolic pressuredata.
 2. The pressurometer interface circuit of claim 1 furthercomprising: means for adjusting the signal level of said receivedplurality of bilevel signals to a predetermined range of levelscompatible with said interface circuit.
 3. The pressurometer interfacecircuit of claim 1 further including: means responsive to deflation ofthe pressurometer cuff for generating pulses coincident with patientKorotkoff sounds; and means responsive to cuff exhaustion for inhibitingthe generation of said pulses and for enabling sampling by said samplingmeans of said plurality of bilevel signals.
 4. In combination with apressurometer interface circuit of the type claimed in claim 1 furtherapparatus including: means for transmitting said generated serial bitform address signal; a test station console for receiving said addresssignal; and a central computation facility in communication with saidconsole for data processing of said address signal as received by saidconsole to provide diastolic and systolic pressure data; said console,in association with said central computation facility, having meansresponsive to said diastolic and systolic pressure data from saidcentral computation facility for displaying said data at said console;said console further having means for causing said central computationfacility to record said diastolic and said systolic pressure data inresponse to activation thereof.
 5. The apparatus and pressurometerinterface circuit of claim 4 further including means for causingrecycling of said interface and pressurometer for additional testing inresponse to activation thereof.
 6. The pressurometer interface circuitof claim 1 wherein said sampling means further includes: a multiplexersystem receiving said plurality of adjusted, bilevel signals at parallelinputs thereof; and a counter operating at a predetermined frequency tocount through a predetermined number of steps; said multiplexer systemoperating in response to the counting of said counter to provide at anoutput of said multiplexer system said sequence of sampled signals; eachstep in the count of said counter causing said multiplexer to provide atthe output thereof one signal of said sequence of sampled signals incorrespondence with that step in the count.
 7. The pressurometerinterface circuit of claim 1 wherein said address signal generatingmeans includes means for providing an indication in said address signalof the level of one said adjacent, different bilevel signals.
 8. Thepressurometer interface circuit of claim 1 wherein said sampling meansincludes means for providing a signal of a predetermined level in saidsequence to indicate the end of said sequence.
 9. An interface circuitoperative in association with a blood pressurometer of the type having ablood flow restricting inflatable cuff cyclable through an inflate anddeflate sequence and adapted to sense the Korotkoff sounds during atleast a portion of the sequence, said pressurometer further including aplurality of two display state elements each associated with aparticular pressure in a range of pressures for said cuff, saidpressurometer adapted to cause each of said two state elements to changefrom a first display state to a second display state in response to theexistence of said Korotkoff sounds at the corresponding pressure levelof each said element during deflation of said cuff, said interfacecircuit comprising: means for sensing the state of each of saidplurality of two state elements; means for developing a plurality ofbilevel signals, each representative of the sensed state of acorresponding two state element; means for adjusting each said bilevelsignal in signal level to a predetermined data logic scheme; multiplexermeans for receiving each of said plurality of bilevel signals on one ofa plurality of parallel inputs; a binary counter operative to count at apredetermined rate through a predetermined number of binary steps; saidmultiplexer means being operative in response to the count of saidcounter to provide as an output signal, a signal representative of thelevel of an input to said receiving means corresponding to the count ofsaid counter in order to provide at the output of said multiplexer meansa sequence of signals representative of the signal level at each of saidplurality of parallel inputs to said multiplexer means; means forsampling and retaining for approximately one step of said coUnter eachsignal in said sequence of signals at the output of said multiplexermeans; means for comparing each signal in the sequence of signals fromsaid multiplexer means with the signal retained by said sampling andretaining means; said comparing means providing an indication of adifference between adjacent signals at the output of said multiplexermeans; and means for generating a signal representative of the count ofsaid binary counter coincidental with the indication by said comparingmeans of different adjacent signals in said sequence.
 10. The interfacecircuit of claim 9 further including: means for sensing Korotkoff soundsignals from said pressurometer; means for producing a signalrepresentative of said sensed Korotkoff sound signals; means for sensingthe state of inflation of said cuff by said pressurometer; means forenabling the production of said signals representative of Korotkoffsound signals only during relatively noise free portions of aninflate-deflate cycle; and means for inhibiting said counter wheneversaid sensed cuff status indicates partial or complete cuff inflation;said counter being operative in response to said sensed cuff status tocommence counting at a predetermined count whenever said cuff statussignal indicates cuff exhaustion after an inflate-deflate cycle.
 11. Theinterface circuit of claim 10 further including: means for indicatingthe inflation status of said cuff; means responsive to the indicateddeflation of said cuff and the sensed Korotkoff sounds for producingpatient pulse signals in serial bit form; and means for alternativelytransmitting said generated and said produced signals.
 12. The interfacecircuit of claim 9 wherein said generating means further includes:second multiplexer means for receiving the binary states of saidcounter; a second counter counting at a predetermined higher rate thanthe first mentioned counter; said second multiplexer means includingmeans responsive to the count sequence of said second counter forproviding as an output a sequence of signals representative of thebinary states of said first counter as applied to said secondmultiplexer means.
 13. The interface circuit of claim 9 furtherincluding means for causing said generating means to generate an end ofsequence signal when said binary counter has counted through saidpredetermined number of binary steps.
 14. The interface circuit of claim9 having apparatus associated therewith including: a serial bit datalink means for applying said generated signal to said data link; controlmeans for recovering said generated signal from said data link and forapplying a supervisory signal to said data link; said interface circuitincluding means for recovering said supervisory signal from said datalink and for applying said recovered supervisory signal to control saidbinary counter; said control means having means for determining anddisplaying patient cardiovascular data in response to said recoveredgenerated signal and further including means having first and secondstates to record said data in said first state and to enable, with saidsupervisory signal, said interface circuit to generate further signalsin said second state.
 15. The interface circuit and apparatus of claim14 further including: a tonometer test unit; and an electrocardiographtest unit; means for interconnecting said units with said control meansfor processing received test information.